In conventional pneumatic tires for passenger vehicles, the main internal structure or carcass of the tires includes a pair of beads and a plurality of plies wrapped from the first bead to the second bead to define a generally U-shaped cross-section. The plies are rubber-coated fabric cords composed of materials such as polyester. The plies are typically wrapped to extend either generally perpendicular to the pair of beads (as shown in FIG. 5 and referred to as a “radial” construction) or angled to the pair of beads (referred to as a “bias” construction). The plies define the primary structural component of a pneumatic tire and transfer forces from a tread of the tire to the beads and therefore the rims of the tire. Ply construction is well-known in the art and is generally successful for its intended purpose, which is to maintain the size and shape of the tire and transfer loads applied to the tire.
However, conventional tires constructed with plies suffer from certain drawbacks. For example, the tightly wrapped polyester cords typically define miniscule spaces or “rivet areas” between adjacent cords. These rivet areas comprise mostly rubber instead of polyester material and therefore have a lessened localized resistance to a puncturing force applied to the carcass as compared to the polyester cords. As a result, the entire carcass of a conventional tire defines a completely discontinuous puncture resistance which negatively affects the overall performance and durability of the tire.
Furthermore, the tire manufacturing process is complex in part because forming the carcass with plies is a complex process. The polyester cord forming the plies must be calendared, accurately wound about the pair of beads, and coated with rubber material. The winding of the plies typically requires an intricate piece of machinery to ensure that adjacent plies are contacting each other and to ensure that the ply angle with respect to the beads is maintained, whether the tire is a radial construction or a bias construction. Thus, the formation of the carcass significantly increases the amount of time required to manufacture a pneumatic tire.
There is a need, therefore, for an improved pneumatic tire that addresses these and other issues associated with conventional tires.